Definition of treacherous in English:

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Pronunciation: /ˈtrɛtʃ(ə)rəs/


1Guilty of or involving betrayal or deception: a treacherous Gestapo agent memory is particularly treacherous
More example sentences
  • Josh had been promoted recently because of a treacherous betrayal by the old Number Four.
  • For example, he embodied animals that were weak, cowardly, false, and treacherous.
  • They are not deceitful or treacherous in their conduct and are faithful to their oaths and promises.
traitorous, disloyal, perfidious, faithless, unfaithful, duplicitous, false-hearted, deceitful, false, untrue, back-stabbing, double-crossing, double-dealing, two-faced, Janus-faced, untrustworthy, unreliable, undependable, fickle;
apostate, renegade, subversive, seditious, rebellious, mutinous, breakaway;
treasonable, treasonous
informal two-timing
rare Punic
2(Of ground, water, conditions, etc.) presenting hidden or unpredictable dangers: a holidaymaker was swept away by treacherous currents
More example sentences
  • My inertia in not pushing it backwards into a safe zone is as guilty for the shattered glass as the treacherous wind.
  • On that day Couples' tee-shot to Golden Bell, the treacherous par three, clung miraculously to the bank of the Creek.
  • The views open out to the north-east, across the treacherous Pentland Firth to Orkney, as you reach Portskerra pier.
dangerous, hazardous, perilous, unsafe, precarious, risky, deceptive, unreliable, undependable, unstable;
icy, ice-covered, slippery, glassy
informal dicey, hairy, slippy
North American informal gnarly



Pronunciation: /ˈtrɛtʃ(ə)rəsli/
Example sentences
  • As it was, hopeful rather than thoughtful balls were plummeted into a two man full-forward line that had virtually no chance of securing possession given the tendency of the ball to skid away from them on the treacherously greasy surface.
  • It rained heavily during the afternoon, which made the stages very muddy and treacherously slippy.
  • I defy anyone who hasn't read the book to decipher this film, to understand the implications, motivations and emotional complexities of a story dependent on treacherously subtle codes of conduct.


Pronunciation: /ˈtrɛtʃ(ə)rəsnəs/
Example sentences
  • The introduction speaks of the harshness and treacherousness of the Antarctic - so much so that I actually felt a chill.
  • Fairbanks is made out to be a pretty dangerous town with flights in the winter operating perhaps only a few times a week due to the difficulty and treacherousness of getting around the ice fog.
  • Thus far, their collected data confirm the treacherousness of the bottom.


Middle English (in sense 1): from Old French trecherous, from trecheor 'a cheat', from trechier 'to cheat'.

Words that rhyme with treacherous


For editors and proofreaders

Line breaks: treach|er¦ous

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